Certain medical conditions require long term access to a person's stomach for the purpose of internal feedings and/or delivering medications. Often this is accomplished by inserting a gastrostomy device through an opening in the wall of the abdomen and into the stomach of a patient to supply nutrients and other fluids, including medications. Various types of gastrostomy devices have been installed in patients by means of percutaneous insertion, surgical placements, radiological placement or others. Once installed, these devices are retained in place by an internal retention member which functions to not only maintain the device in place but also to prevent leakage. Currently, there are several types of internal retention members on the market, e.g., molded or permanently attached flange elements, collar and balloon members, etc.
The particular materials to be utilized for internal retention members in a gastrostomy device must be biocompatible with the gastric environment. Such materials should also be resistant to acidic and enzymatic degradation in order to remain stable within the stomach for a long period of time, which reduces the frequency of replacement of the device and the risk of infection and trauma. In the past, the internal retention members have been made from elastomeric materials, such as latex materials or silicone elastomers. These materials have been found to be well suited for use in the construction of the internal retention members. The present invention, however, is directed to further improvements in internal retention members used in conjunction with a gastrostomy device. In particular, the present invention is directed to constructing internal retention members from materials that have improved resistance to acidic and/or enzymatic degradation when placed in the stomach of a patient.